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b=T+GJemKqcfjH+eJfUxIxu0Gn0AT8tZ0Ag2+bEaXYFqR3pypLsiGlw2ABHI3lVk5Xk6MSRDmz1VWx0iuTsr1j99a30ILZDmWtzzgml2cKob7D+yaIkUv+HfnvM04qmJJ/MUGHvRNmgVd0SlD6ULc+5Ve4PUMGzK+IAr3dIdDeOa0= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from BN8PR12MB3268.namprd12.prod.outlook.com (2603:10b6:408:6c::18) by SA1PR12MB8164.namprd12.prod.outlook.com (2603:10b6:806:338::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7181.17; Wed, 10 Jan 2024 22:17:24 +0000 Received: from BN8PR12MB3268.namprd12.prod.outlook.com ([fe80::cc71:1a30:afcb:c569]) by BN8PR12MB3268.namprd12.prod.outlook.com ([fe80::cc71:1a30:afcb:c569%7]) with mapi id 15.20.7159.015; Wed, 10 Jan 2024 22:17:24 +0000 Message-ID: <3f2b728e-6484-48e4-b59e-eab41d293b66@amd.com> Date: Wed, 10 Jan 2024 16:17:20 -0600 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 4/5] cxl/core, EINJ: Add CXL debugfs files and EINJ functions Content-Language: en-US To: Dan Williams , dave@stogolabs.net, jonathan.cameron@huawei.com, dave.jiang@intel.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, rafael@kernel.org Cc: linux-cxl@vger.kernel.org, linux-acpi@vger.kernel.org References: <20231213223702.543419-1-Benjamin.Cheatham@amd.com> <20231213223702.543419-5-Benjamin.Cheatham@amd.com> <65812045c086b_71549294aa@dwillia2-mobl3.amr.corp.intel.com.notmuch> <83ab6ac9-8e64-475e-8ef3-a605cfafedac@amd.com> <659f15d1b4a6e_5cee2946e@dwillia2-xfh.jf.intel.com.notmuch> From: Ben Cheatham In-Reply-To: <659f15d1b4a6e_5cee2946e@dwillia2-xfh.jf.intel.com.notmuch> Content-Type: text/plain; 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>>>> + >>>> + debugfs_create_file("einj_inject", 0200, dir, dport, >>>> + &cxl_einj_inject_fops); >>> >>> I will note that I am little bit uneasy about this ACPI'ism escaping >>> into the common core, but he mitigation for me is that if some other >>> platform firmware invented a platform-firmware method for error inject >>> it would simply need to reuse the einj_cxl_ namespace to make it common. >>> >> >> I'll be honest; I'm not sure I understand the concern here, but that's probably >> just inexperience on my part. That being said, I don't mind changing it if you >> have any suggestions! >> > > Notice how the CXL subsystem organizes all the ACPI interface concerns > into drivers/cxl/acpi.c. There are some generic callbacks like the > @calc_hb argument to cxl_root_decoder_alloc(), but there are no direct > ties of the CXL core code to ACPI details. This separation allows, in > principle, a non-ACPI platform (like PowerPC OpenFirmware) to support > CXL without needing to unwind a bunch of CXL-ACPI specific stuff. > > This "cxl_einj" work is leaking an ACPI specific term "EINJ" into the > core code. The reason I am ok with this is that the ABI is still gated > on CONFIG_ACPI_APEI_EINJ. Also, we still have the option to require that > OpenFirmware error injection just call their user facing ABI "EINJ" as > well, even if it is a different name in the OpenFirmware specification. > To be clear though no one has sent patches for CXL support on anything > other than ACPI based platforms. Ok that makes sense, thanks for the explanation!